I am customizing a laptop computer with a 3740QM and 680M. Now, my reseller for this computer (which, by the way, is a Sager NP9150 or Clevo P150EM) has offered an overclocking option. They claim to significantly increase performance while eliminating too much temperature rise or instability. What worries me most is the effect on battery power. Will overclocking the system take a huge chunk out of my battery life? I'm okay with a battery life over 3 hours. When I am using it on battery power, I will probably have minimum brightness and probably no keyboard backlight.